1. Field of the Invention
This invention relates to organic materials which are useful in the photographic field. In particular, this invention relates to radiation sensitive polymeric organic materials, which can be incorporated into radiation sensitive elements, such as photoresists, to obtain a desirable combination of properties. These polymeric materials are homopolymers or interpolymers comprising oxygen-substituted maleimides, prepared by free radical-initiated addition polymerization.
2. Description of the Prior Art
Applicant has found no art which teaches or suggests the present invention. Schwartz et al report in J. Org. Chem, Vol. 39 (1), pp. 21-23 (1974) the synthesis of an O-substituted maleimide. The specific compound prepared was 0-(1-adamantyl) maleimide, or preferably named as 5-(1-adamantyloxy)-2H-pyrrole-2-one. However, this article does not teach or suggest polymerization of this material or consider any potential polymeric applications.
Several researchers have reported on the photochemical reactivity of keto imine ethers and have postulated mechanisms for such reactivity, notably Koch et al in Tetrahedron Letters, No. 27, pp. 2391-2393 (1970); No. 39, pp. 4035-4038 (1972); and J. Amer. Chem. Soc., Vol. 95 (12), pp. 3957-3963 (1973). The photo initiated rearrangement of keto imino ethers to the corresponding isocyanates is thought to proceed by the following mechanism: ##STR2## None of these articles suggest the polymerization of such keto imino ethers to form polymers which are selectively soluble in organic solvents after irradiation with light.